<template>
	<view class="u-wrap">
		<view class="load" v-if="loading">
			<u-loading mode="circle" size="50" color="rgb(146, 200, 255)" style="position: relative;bottom:100rpx;"></u-loading>
		</view>
		<view class="u-menu-wrap" style="background-color: #f6f6f6;">
			<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop">
				<view v-for="(item,index) in tabbar" :key="index" class="u-tab-item" :class="[current==index ? 'u-tab-item-active' : '']"
				 :data-current="index" @tap.stop="swichMenu(index)">
					<text class="u-line-1">{{item.name}}</text>
				</view>
			</scroll-view>
			<block v-for="(item,index) in tabbar" :key="index">
				<scroll-view scroll-y class="right-box" v-if="current==index">
					<view class="page-view">
						<view class="class-item">
							<view class="item-title">
								<text>{{item.name}}</text>
							</view>
							<view class="item-container">
								<view v-show="current==0" class="library-all">
									<u-row>
										<u-col span="6" v-for="(item, index) in typeList" :key="index">
											<view class="library-item" :key="index" @click="handleToList(item.name,item.id)">
												<u-image width="150rpx" height="200rpx" :src="item.bookList[0].image" mode="cover" :fade="true" duration="450"
												 border-radius="12">
													<u-loading slot="loading"></u-loading>
												</u-image>
												<text style="margin-top:20rpx">{{item.name}}</text>
											</view>
										</u-col>
									</u-row>
								</view>
								<view v-show="current==1" class="library-other">
									<book-list :list="clickList" />
								</view>
								<view v-show="current==2" class="library-other">
									<book-list :list="overList" />
								</view>
								<view v-show="current==3" class="library-other">
									<book-list :list="updateList" />
								</view>
								<div v-show="current === index+4" v-for="(item, index) in typeList" :key="index" class="library-other">
									<book-list :list="item.bookList" />
									<view @click="handleToList(item.name,item.id)" style="display: flex;justify-content: center;align-items: center;height: 80rpx;">
										查看更多
									</view>
								</div>
							</view>
						</view>
					</view>
				</scroll-view>
			</block>
		</view>
		<u-toast ref="uToast" />
		<u-tabbar v-model="currentTabbar" :list="vuex_tabbar"></u-tabbar>
	</view>
</template>

<script>
	import {
		getTypeList,
		getOverList,
		getUpdateList,
		getClickList
	} from '../../api/homepage.js'
	import BookList from '../../components/BookList'
	const defalutTabbar = [{
		name: '所有分类'
	}, {
		name: '点击榜'
	}, {
		name: '完结榜'
	}, {
		name: '更新榜'
	}]
	export default {
		name: 'libary',
		components: {
			BookList
		},
		data() {
			return {
				tabbar: [],
				scrollTop: 0, //tab标题的滚动条位置
				current: 0, // 预设当前项的值
				menuHeight: 0, // 左边菜单的高度
				menuItemHeight: 0, // 左边菜单item的高度
				typeList: [],
				clickList: [],
				updateList: [],
				overList: [],
				loading: false,
				currentTabbar: 0
			}
		},
		onLoad(option) {
			this.loading = true;
			this.getTabbar();
		},
		methods: {
			getTabbar() {
				getTypeList().then((res) => {
					this.typeList = res.data;
					this.tabbar = this.$u.deepClone(defalutTabbar);
					this.typeList.forEach(item => {
						this.tabbar.push(item)
					});
					this.loading = false;
				})
			},
			getClickList() {
				getClickList().then(res => {
					this.clickList = res.data.bookList.data;
				})
			},
			getUpdateList() {
				getUpdateList().then(res => {
					this.updateList = res.data.bookList.data;
				})
			},
			getOverList() {
				getOverList().then(res => {
					this.overList = res.data.bookList.data;
				})
			},
			getImg() {
				return Math.floor(Math.random() * 35);
			},
			// 点击左边的栏目切换
			async swichMenu(index) {
				if (index == this.current) return;
				this.current = index;
				// 如果为0，意味着尚未初始化
				if (this.menuHeight == 0 || this.menuItemHeight == 0) {
					await this.getElRect('menu-scroll-view', 'menuHeight');
					await this.getElRect('u-tab-item', 'menuItemHeight');
				}
				// 将菜单菜单活动item垂直居中
				this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
				switch (index) {
					case 1:
						if (this.clickList.length === 0) {
							this.getClickList();
						}
						break;
					case 2:
						if (this.overList.length === 0) {
							this.getOverList();
						}
						break;
					case 3:
						if (this.updateList.length === 0) {
							this.getUpdateList();
						}
						break;
				}
			},
			// 获取一个目标元素的高度
			getElRect(elClass, dataVal) {
				new Promise((resolve, reject) => {
					const query = uni.createSelectorQuery().in(this);
					query.select('.' + elClass).fields({
						size: true
					}, res => {
						// 如果节点尚未生成，res值为null，循环调用执行
						if (!res) {
							setTimeout(() => {
								this.getElRect(elClass);
							}, 10);
							return;
						}
						this[dataVal] = res.height;
					}).exec();
				})
			},
			// 跳转列表页
			handleToList(title, type) {
				uni.navigateTo({
					url: `/pages/list/list?title=${title}&type=${type}`
				})
			}
		}
	}
</script>

<style lang="scss" scoped>
	.u-wrap {
		height: calc(100vh);
		/* #ifdef H5 */
		height: calc(100vh - var(--window-top));
		/* #endif */
		display: flex;
		flex-direction: column;
	}

	.u-search-box {
		padding: 18rpx 30rpx;
	}

	.u-menu-wrap {
		flex: 1;
		display: flex;
		overflow: hidden;
	}

	.u-search-inner {
		background-color: rgb(234, 234, 234);
		border-radius: 100rpx;
		display: flex;
		align-items: center;
		padding: 10rpx 16rpx;
	}

	.u-search-text {
		font-size: 26rpx;
		color: $u-tips-color;
		margin-left: 10rpx;
	}

	.u-tab-view {
		width: 200rpx;
		height: 100%;
	}

	.u-tab-item {
		height: 110rpx;
		background: #f6f6f6;
		box-sizing: border-box;
		display: flex;
		align-items: center;
		justify-content: center;
		font-size: 26rpx;
		color: #444;
		font-weight: 400;
		line-height: 1;
	}

	.u-tab-item-active {
		position: relative;
		color: #000;
		font-size: 30rpx;
		font-weight: 600;
		background: #fff;
	}

	.u-tab-item-active::before {
		content: "";
		position: absolute;
		border-left: 4px solid rgb(146, 200, 255);
		height: 32rpx;
		left: 0;
		top: 39rpx;
	}

	.u-tab-view {
		height: 100%;
	}

	.right-box {
		background-color: rgb(250, 250, 250);
	}

	.page-view {
		padding: 16rpx;
	}

	.class-item {
		margin-bottom: 30rpx;
		background-color: #fff;
		padding: 16rpx;
		border-radius: 8rpx;
	}

	.item-title {
		font-size: 26rpx;
		color: $u-main-color;
		font-weight: bold;
	}

	.item-menu-name {
		font-weight: normal;
		font-size: 24rpx;
		color: $u-main-color;
	}

	.item-container {
		display: flex;
		flex-wrap: wrap;
	}

	.thumb-box {
		width: 33.333333%;
		display: flex;
		align-items: center;
		justify-content: center;
		flex-direction: column;
		margin-top: 20rpx;
	}

	.item-menu-image {
		width: 120rpx;
		height: 120rpx;
	}

	.library-all {
		display: flex;
		flex-wrap: wrap;
		justify-content: space-evenly;
		align-items: center;
	}

	.library-item {
		display: flex;
		flex-direction: column;
		align-items: center;
		margin: 40rpx;
	}

	.library-other {
		width: 100%;
	}

	.load {
		position: fixed;
		top: 0;
		left: 0;
		height: 100vh;
		width: 100vw;
		display: flex;
		align-items: center;
		justify-content: center;
		background: white;
		z-index: 10;
	}
</style>
